Combination padlock

ABSTRACT

A combination padlock of the single dial type is constructed so that manipulation of the shackle enables changing or setting the combination, thereby eliminating additional elements to accomplish this function. The padlock employs a floating fence member which acts as a single or double lever on different occasions. A key-actuatable bolt cooperable with the fence member enables the padlock to be opened by a key.

[4 1 July 15, 1975 United States Patent 191 Balto Primary Examiner-Robert L. Wolfe Attorney, Agent, or Firm-Shapiro and Shapiro [22] Filed: Mar. 25, 1974 [2]] Appl. No..- 454,420

ABSTRACT 52 us. Cl. 70/21; 70/25; 70/316; A Combination Padlock of the Single dial yp is structed so that manipulation of the shackle enables changing or setting the combination ing additional elements to accom The padlock employs a floating fe 70/321 E05b 37/10 70/2l, 25, 316, 317, 318,

thereby eliminatplish this function.

[58] Field of Search nce member which acts as a single or double lever on different occasions [56] References Cited A key-actuatable bolt cooperable with the fence mem- UNITED STATES PATENTS ber enables the padlock to be opened by a key 10 313 x 21 Claims, 18 Drawing Figures 70/40! X 940,763 ll/l9U9 l,804.955 5/l93l Schlumpf.....l....t.........H....

whim-Mill Hui SHEET SHEEY FIlLI-I Fl G15 FIGIS FIG]? COMBINATION PADLOCK The invention relates to combination padlocks and is more particularly directed to improvements in single dial combinations padlocks of the type including means for setting or changing the combination.

BACKGROUND OF THE INVENTION Single dial combination padlocks of the type having means for changing the combination are known. See, for example, US Pat. Nos. 2,090,631, 2,154,660, 2,330,447, 2,852,928, and 3,533,253. However, these padlocks require either that the padlock be partially disassembled or that a key or other tool be employed to change the combination.

In US. Pat. No. 3,729,962, a combination padlock has tumblers with rim and hub portions connected through a friction clutch type connection. By actuating an externally mounted lever (movable only when the shackle is in open position) the hubs may be rotated relative to the rims by the dial for setting a combination of ones own choice. The external lever of this padlock invites tampering which may damage the combinationchanging mechanisms. Furthermore, because combination locks tempt persons to manipulate them before becoming familiar with the written instructions which accompany the lock, the combination may inadvertently be changed to a new combination unknown to the user, particularly since the combination is set with the shackle in the usual open position. The lock must then be returned to the manufacturer who expends considerable effort in opening it, if possible. Moreover, because the lever must be manipulated with the fingers, the degree to which this prior art device may be miniaturized is limited.

SUMMARY OF THE INVENTION A primary object of the invention is to provide a combination padlock which enables the combination to be changed without disassembling the padlock and without using a key or other tool, and which eliminates obstrusive means on the padlock for changing the combination.

Another object of the invention is to provide a combination padlock having an improved and simplified locking mechanism.

Still another object of the invention is to provide a combination padlock having an improved mechanism for enabling the padlock to be opened by a key in the event that the combination is forgotten.

A single-dial combination padlock made in accordance with the invention comprises a body having an internal cavity and a shackle of the usual type (i.e., having a long leg portion and a short leg portion) mounted on the body so that the long leg portion extends into the internal cavity. The shackle is movable to the usual open first position and closed second position and is further movable to a combination-changing third position. A plurality of tumblers in the internal cavity are positionable by a manually rotatable dial mounted on the body. A single floating fence member is cooperable with notches in the peripheries of the tumblers for locking the shackle in the closed position except when the tumblers are set to the opening combination. When the shackle is moved from the usual open position to the combination-changing third position, the combination of the padlock may be changed merely by turning the dial to the desired new combination.

The above-described objects and advantages of the invention, as well as other objects and advantages, will be apparent from the following detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further described in conjunction with the accompanying drawings, which illustrate a preferred and exemplary embodiment, and wherein:

FIG. 1 is a front elevational view of a combination padlock made in accordance with the invention;

FIG. 2 is an enlarged front elevational view of the padlock with the dial removed and with a key inserted in the padlock, this view showing the padlock casing cut away and in cross section;

FIG. 3 is a transverse cross-sectional view taken approximately in the plane of line 3-3 of FIG. 2;

FIG. 4 is a longitudinal cross-sectional view taken approximately in the plane of line 44 of FIG. 2;

FIG. 5 is an enlarged perspective view of a fence member employed in the padlock of FIGS. l-4;

FIGS. 69 illustrate the various operating positions on the fence member of FIG. 5 and associated parts of the padlock;

FIG. 10 is an exploded perspective view of the tumblers, tumbler drivers, and combination-changing mechanism of the padlock of FIGS. l-4;

FIGS. 11-14 illustrate the various operating positions of the combination-changing mechanism of FIG. 10 and associated parts of the padlock;

FIG. 15 is a rear elevational view of the padlock, this view showing a keyhole in the casing;

FIG. 16 is a plan view of a key receivable by the keyhole shown in FIG. 15 for opening the padlock; and

FIGS. 17 and I8 illustrate the operating positions of a bolt member employed in the padlock, the bolt member being rotatable by the key of FIG. 16 for unlocking the padlock without dialing the combination.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, a single-dial combination padlock made in accordance with the invention essentially comprises a body A, a shackle B, a manually rotatable dial C, a plurality of tumblers Dl-D3, and a floating fence member E. A tumbler shifter assembly F is provided to enable changing or setting the combination to a combination of ones own choice. An annular bolt G rotatable by a key H is provided for enabling the padlock to be opened without dialing the combination, a condition which is dictated when one forgets or loses the combination.

As shown in FIGS. 2-4, body A comprises a frame 10 enclosed in a casing II which comprises a side wall 12, which may be cylindrical as illustrated, having one end closed by a wall 13 for forming the rear surface of the padlock. For convenience of manufacture and to mini mize the number of parts, it is preferred that the frame be made by die-casting. As shown in FIGS. 3 and 4, the upper edge portion 14 of side wall 12 is bent over sections 34, 36 and 38 of an annular rim on the frame for securing the manually rotatable dial C to the body. The dial is urged outwardly from the body by a dial spring 16 comprising a coil spring which encircles hub portion 18 of the dial and which acts against shifter plate 48 of shifter F (to be described later) to bias the upper surface of peripheral rim of the dial against edge portion 14 of the casing. Inward movement of the dial relative to body A is restricted by the interaction of the bottom surface of rim 20 of the dial with surfaces 22, 24, 26, and 28 of frame 10, shown best in FIG. 2.

Shackle B has the usual .I-shaped configuration with the long leg portion extending through an opening 41 in casing side wall 12 and into a body cavity enclosed by frame 10 and dial C, the long leg portion being slidably supported by the frame for enabling the shackle to be axially moved between the usual open and closed positions. The short leg portion 43 of the shackle is received by an opening 44 in casing side wall 12 when the shackle is in the closed position. A stop wall 46 on frame 10 in alignment with opening 44 limits movement of the shackle into the frame to the closed position, as shown in FIG. 2. However, if the shackle is rotated from the usual open position (see FIG. 7) to another position so that the end of the short leg portion of the shackle does not enter opening 44 of the casing when the shackle is pushed into body A, the long leg portion of the shackle may be pushed further into the body to a combination-changing position (see FIG. 13) to be subsequently described.

Referring to FIGS. 4 and 10, three annular gate tumblers D1, D2 and D3 are supported centrally in the body cavity by a tumbler shifter assembly F comprising the shifter plate 48 and a pair of spaced, parallel side plates 50 and 52 carried by the shifter plate. As shown in FIG. 3, dial spring 16 acts against the intermediate portion of the shifter plate to bias a lug 54 at one end of the plate against the sloping bottom surface 56 of a recess 57 (FIG. 2) between rim sections 36 and 38 of the frame and to bias bent portion 58 at the other end of the shifter plate into engagement with surface 60 of a guide plate 62 which is carried in an annular recess 64 in the long leg portion of the shackle. As shown in FIG. 2, the shifter plate is also held in position in the body cavity by walls 65 and 66 of the frame. Referring to FIGS. 2 and 4, side plates 50 and 52 have slots 67 and 68, respectively, which receive lugs or ears 70 and 71 on the shifter plate, the lugs being movable to a lim' itcd extent in the slots so as to enable the shifter plate to float" in the body cavity. Consequently, when dial C is turned, teeth 72 on the dial hub 18 (see FIG. 4) produce a ratcheting sound and feeling as they pass over a single tooth 73 on the shifter plate (FIG. 10). Tooth 73 is slightly off center in relation to the teeth 72 on the dial.

As shown in FIG. 4, wall 65 of the frame maintains the parallel, elongated slots 74, 76 and 78 of side plate 50 in receiving engagement with portions of the peripheral edges of gate tumblers D1, D2 and D3, respectively, and wall 66 maintains similar slots 80, 82 and 84 of side plate 52 in receiving engagement with edge portions diametrically opposite the portions received by the slots of side plate 50. When shifter plate 48 is in its normal position, shown in FIGS. 24, teeth on the inner periphery of annular gate tumbler D1 engage teeth 72 on dial hub 18 for enabling that gate tumbler to be rotated with the dial C.

Annular gate tumblers D2 and D3 are identical in configuration to gate tumbler D1, but are rotatable by associated driver tumblers 96 and 98, respectively. The driver tumblers are rotatably supported on a shoulder 100 of a stud 102 provided by frame 10(FIG. 10), the

end of the stud being received by an opening 103 in dial hub 18, as shown in FIGS. 3 and 4. The driver tumblers are axially spaced on the stud by a center spacer 104. A second center spacer 106 carried by the stud in a position between dial C and driver tumbler 96 is cooperable with the bottom surface 108 of dial hub 18 for maintaining the driver tumblers on the stud in the positions shown. As shown in FIG. 4, a lug 114 projecting from surface 108 of the dial hub is cooperable with an upturned lug 116 on driver tumbler 96 for enabling that driver tumbler to be positioned by dial C. A downturned lug 118 on driver tumbler 96 is cooperable with an upturned lug 120 on driver tumbler 98 for enabling driver tumbler 98 to be positioned by driver tumbler 96.

Referring to FIGS. 3 and 10, when shifter plate 48 is in the normal position shown in FIGS. 2-4, gear teeth 110 and 1 12 on the outer peripheries of driver tumblers 96 and 98, respectively, engage the toothed inner peripheries 90 of annular gate tumblers D2 and D3, respectively, for enabling those gate tumblers to be rotated with the driver tumblers.

As shown in FIG. 10, each gate tumbler is provided with a notch 126 in its outer periphery. When shifter plate 48 is in normal position, rotation of dial C to the three-number opening combination in the usual manner positions the gate tumblers such that the notches 126 are aligned for receiving a projection on the fence member E, thereby unlocking the shackle in a manner to be described subsequently. Each gate tumbler is further provided with a downturned lug 122, of which lug 122 on gate tumbler D3 is cooperable with a flag 124 on guide plate 62 (see FIG. 3) for scrambling the combination when the shackle is pulled from body A to the open position.

Referring to FIG. 5, the locking means or fence member E comprises an elongated plate having a notch in its side in end portion 131 of the plate, the notch receiving a wall or rail 132 on the frame, as shown in FIGS. 2 and 8, for slidably connecting end portion 131 of the fence member to the frame. A rectangular opening 134 near the opposite end portion 135 of the plate is cooperable with a projection 136 on short leg portion 46 of shackle B for releasably locking the shackle in the closed position, as shown in FIGS. 2 and 9. End portion 135 of the fence member curves away from the short leg portion of the shackle when the shackle is in the closed position for reasons which will be described later. The intermediate portion of the plate is formed to provide a projecting rib 138 which is adapted to be received by notches 126 in the peripheries of the gate tumblers Dl-D3 when the tumblers are set to the opening combination. As shown in FIGS. 2 and 3, a coil spring 140 has one end received by a recess 142 in frame 12 and receives in its other end a stud 144 on the fence member between notch 130 and rib 138.

Fence member E is essentially a floating member which works as a single or double-acting lever on different occasions. Under constant pressure from coil spring 140, end portion 131 of the fence member is biased against the side of a rib or wall 146 formed at one end of rail 132, while rib 138 of the fence member is biased against the peripheries of gate tumblers Dl-D3, as shown in FIGS. 2, 7 and 9. Because the fence spring 140 acts between the two contact points 131 and 138, the fulcrum of the fence members lever action can be shifted to either of these two points Operation of fence member E will now be described with reference to FIGS. 6-9. FIG. 9 shows shackle B in closed position wherein coil spring 140 biases rib 138 of the fence member against the peripheries of the gate tumblers (only gate tumbler D3 being shown) and biases end portion 131 against the side wall 146, thereby causing projection 136 of the short leg portion of the shackle to be received in opening 136 of the fence member for locking the padlock. Referring to FIG. 6, rotating dial C to the opening combination of the padlock positions the gate tumblers such that notches 126 in the peripheries of the gate tumblers are aligned for receiving rib 138 of the fence member, thereby permitting spring 140 to pivot the fence member about its point of contact with wall 146 sufficiently to disengage projection 136 of the short leg portion of the shackle from the opening 134 of the fence member. The

shackle can then be pulled out of body A to the usual open position shown in FIG. 7. As the shackle is being pulled from the body. flag 124 on guide 62 (shown best in FIG. 3) engages downturned lug 122 on the bottom gate tumbler D3 for causing that tumbler to be rotated to the position shown in FIG. 7, thereby scrambling the combination. Because notch 126 of gate tumbler D3 is moved out of receiving engagement with rib 138 of the fence member. the fence member is returned to its locking position, as shown in FIG. 7.

Referring to FIG. 8, as the shackle is pushed into the body to the closed position for locking the padlock, the end of the short leg portion of the shackle is brought into sliding contact with curved end portion 135 of the fence member. The resulting camming action causes the fence member to act as a double lever. pivoting about its point of contact at 138 with the peripheries of the gate tumblers, which causes notch 130 in the fence member to slide along rail 132 of the frame against the force of spring 140. When the shackle has been pushed in to the extent that the projection 136 on the shackle reaches opening 134 in the fence member. spring 140 snaps the fence member into locking engagement with the shackle. Further inward movement of the shackle relative to the body is prevented by stop wall 46, shown in FIGS. 2, 6-9 and 13. The arcuate path of the fence member during this action tends to pull the shackle inward further than at its rest position when fully engaged. This means that more spring compression is required at the beginning of the exiting action of the shackle, which tends to hold the shackle in against misuse of the lock.

The combination-changing feature will now be explained with reference to FIGS. 2-4 and 1014. Tumbler shifter assembly F, comprising shifter plate 48 and spaced side plates 50 and 52 which carry the gate tumblers, is actuated by long leg portion 40 of the shackle for enabling the opening combination of the padlock to be changed only when the shackle is in a particular combinatiomchanging position (see FIG. 13), which is different from the usual open and closed positions of the shackle. When the shackle is in the usual closed and open positions, dial spring 16 biases the bent end 58 of shifter plate 48 against surface 60 of guide plate 62, as shown in FIGS. 3 and 12. With the shifter plate in this position, side plates 50 and 52 support the gate tumblers Dl-D3 in engagement with their associated drivers (i.e.. teeth 90 on gate tumbler D1 engage the teeth 72 of dial hub 18 and teeth 90 on gate tumblers D2 and D3 engage the peripheral teeth 110 and 112 of drive tumblers 96 and 98, respectively), and the padlock is operated in the usual manner of a three-number singledial combination padlock.

When it is desired to change the opening combina tion to a new combination. it is necessary that shifter plate 48 be pivoted about its lug 54 to the position shown in FIG. 14 (and shown in phantom at 48' in FIG. 3) for causing side plates 50 and 52 and the gate tumblers Dl-D3 to be shifted in directions parallel to the axis of rotation of the gate tumblers for thereby disengaging the gate tumblers from their associated drivers. The necessary pivoting action of shifter plate 48 is accomplished by the following procedure. Firstly. the padlock is opened by dialing the opening combination and pulling shackle B from body A to the usual open position shown in FIG. 7. Secondly, the shackle is rotated 180 relative to the body and then pushed into the body to the combination-changing position shown in FIG. 13, causing surface 60 of guide plate 62, which is carried by long leg portion of the shackle. to be moved out of supporting contact with bent end 58 of shifter plate 48. However. although the bent end 58 of the shifter plate is now free, dial spring 16 cannot pivot the shifter plate about lug 54 because a lug 150 (see FIG. 11) on the shifter plate still rests upon side edge 152 of fence member E. which is in the locking position as a result of the scrambling action explained above. Therefore, for moving the fence member out of its supporting relationship with lug 150 of the shifter plate, a third step is required in which dial C is again turned to the opening combination. thereby enabling spring to move the fence member to the position shown in FIG. 13 and permitting dial spring 16 to pivot the shifter plate about its lug 54 to the combination-changing position shown in FIG. 14, wherein bent portion 58 of the shifter plate is biased into contact with long leg portion 40 of the shackle. Fence member E is cut away at 154 so as not to restrict the pivoting movement of the shifter plate to this position. Referring to FIG. 2, as the shifter plate pivots, a first pair of spaced guide ribs 650 and 65b on wall 65 of frame 10 and a second pair of spaced guide ribs 660 and 6612 on wall 66 guide the side plates 50 and 52, respectively. in directions parallel to the axis of rotation of the gate tumblers D1-D3, so that the gate tumblers are moved away from dial C along the axis of rotation. thereby disengaging the gate tumblers from their associated drivers (i.e., gate tumbler D1 is moved out of engagement with teeth 72 on dial C and gate tumblers D2 and D3 are moved out of engagement with drive tumblers 96 and 98, respectively). The opening combination of the padlock may now be changed to a new combination by rotating dial C in the usual manner to the desired new combination, which alters the position of dial C relative to gate tumbler D1 and alters the positions of driver tumblers 96 and 98 relative to gate tumblers D2 and D3. To establish a new opening combination of 10-25-18, for example, the numbered dial C (FIG. 1) is turned clockwise past number 10 twice and is stopped at this number the third time around. Then, the dial is turned counterclockwise past number 25 once and is stopped at this number the second time around. Finally, the dial is turned clockwise and is stopped at number 18. The shackle is then pulled outwardly from the body A, which causes shifter plate 48 to be returned to its normal position by the camming action of surface 62 of guide plate 60 with a bent-up lug 156 on the shifter plate, shown in FIGS. 2, 10 and 13. Side plates 50 and 52, carried by the shifter plate, therefore move gate tumblers D1D3 back into engagement with their associated drivers. The combination padlock is then ready for use with the new opening combination.

A key-actuatable bolt G is provided for enabling the padlock to be unlocked by a key. Referring to FIG. 2, bolt G comprises an annular member or ring supported by surfaces 160, 162 and 164 of frame 10. A downturned lug 170 on the bolt abuts one side of a wall 172 on the frame and a downturned lug 174 abuts end portion 131 of fence member E for maintaining the bolt member in the rest position shown in FIGS. 2 and 17. A key H(F1G. 16), preferably formed from a spline shaft, has six teeth 177 equally spaced about its periphery, the key being insertable in a keyhole 178 in the rear of the padlock, shown in FIG. 15. As shown in FIG. 4, when the key is inserted in the keyhole, shaft portion 176 of the key is received by a cylindrical open ing 179 in the wall 66 of the frame for supporting the key with its teeth in engagement with gear teeth 180 on the inner periphery of bolt G. Rotation of the key in the clockwise direction (as viewed in FIGS. 2, 17 and 18) rotates bolt G in the clockwise direction, thereby causing downturned lug 174 of the bolt to move end portion 131 of the fence member along wall 132 away from wall 146 against the action of spring 140. The fence member is thus caused to pivot about the rib 138 for moving opening 134 of the fence member out of engagement with projection 136 of shackle B, as shown in FIG. 18. With the fence member in this position, the shackle may then be pulled from the padlock to the open position. When the torque applied to the key is removed, spring 140 moves end portion 131 of the fence member against downturned lug 174 on the bolt for returning the bolt to the rest position shown in FIGS. 2 and 17.

The configurations of bolt G and key H enable the bolt to be rotated to an extent which cannot be accomplished by manipulation of the bolt by a simple wire or rod inserted in the keyhole. Although it might be possible to move a single tooth on the bolt in this manner, release of the shackle requires that several teeth be actuated against the tendency of fence spring 140 to return the fence member and the bolt to their normal or rest positions. When the bolt is in the rest position shown in FIGS. 2 and 17, counterclockwise rotation of the bolt is prevented by downturned lug 170 which abuts the one side of wall 172 of the frame.

Referring to FIG. 2, a second set of teeth 182 diametrically opposite gearing 180 and a cylindrical channel 183 in wall 65 provide for a different key position and a different key configuration, the key 184 (shown in phantom) having four teeth equally spaced about its periphery.

It is believed that the advantages and improved results furnished by the combination padlock of the in vention will be apparent from the foregoing description of a preferred embodiment of the invention. Various changes and modifications may be made without departing from the spirit and scope of the invention as sought to be defined in the following claims.

1 claim:

1. A combination padlock comprising:

a body having an internal cavity;

a shackle having a long leg portion and a short leg portion, the long leg portion extending into the internal cavity and being slidably supported by the body for enabling the shackle to be moved from an open first position to a closed second position and to a combination-changing third position; a manually rotatable dial supported by the body; a plurality of tumblers contained in the internal cavity, the tumblers being rotatable by the dial;

locking means cooperable with the tumblers for locking the shackle in the closed second position and for unlocking the shackle when the tumblers are set to the opening combination of the padlock; and

combination-changing means actuated by the long leg portion of the shackle when the shackle is moved to the combination-changing third position for enabling the opening combination of the padlock to be changed.

2. A combination padlock as set forth in claim 1, wherein the tumblers releasably engage associated tumbler drivers, the drivers being rotatable by the dial, and wherein the combination-changing means comprises means for disengaging the tumblers from their associated drivers when the shackle is in the combination-changing third position, thereby enabling the drivers to be manually rotated relative to their associated tumblers by the dial for setting a new opening combina tion.

3. A combination padlock as set forth in claim 2, wherein the means for disengaging the tumblers from their associated drivers comprises shifter means for shifting the tumblers relative to their associated drivers in a direction substantially along the axis of rotation of the tumblers.

4. A combination padlock as set forth in claim 3, wherein the shifter means comprises a shifter plate having one end pivotally supported by the body and the other end biased into contact with means provided by the long leg portion of the shackle, the shifter plate carrying a pair of spaced side plates having slots receiving the peripheral edges of the tumblers, movement of the shackle from the open first position to the combination-changing third position causing the side plates to be moved in directions substantially parallel to said axis for moving the tumblers out of engagement with their associated drivers.

5. A combination padlock as set forth in claim 4, wherein the means provided by the long leg portion of the shackle has means for scrambling the combination as the shackle is moved from the closed position to the open position.

6. A combination padlock as set forth in claim 1, wherein the locking means comprises a fence member having one end slidably connected to rail means provided by the body, the fence member having engagement means near its other end for releasably engaging the short leg portion of the shackle to lock the shackle in the closed position, and having projecting means intermediate the one end and the engagement means, and a spring which acts against the fence member between the one end and the projecting means for biasing the one end of the fence member toward one end of the rail means for biasing the projecting means into contact with the peripheries of the tumblers, the engagement means engaging the short leg portion of the shackle for locking the shackle when the shackle is in the closed position and the projecting means being receivable by notches in the peripheries of the tumblers for moving the engagement means out of engagement with the short leg portion of the shackle to unlock the shackle when the tumblers are set to the opening combinations.

7. A combination padlock as set forth in claim 1, further comprising a ring disposed in the internal cavity and rotatable by a key, the ring having means for moving the engagement means of the fence member out of engagement with the short leg portion of the shackle when the ring is rotated in a first direction by the key.

8. A combination padlock as set forth in claim 6, further comprising a ring disposed in the internal cavity and rotatable by a key, the ring having means for moving the engagement means of the fence member out of engagement with the short leg portion of the shackle when the ring is rotated in a first direction by the key.

9. A combination padlock as set forth in claim 1, wherein the combination-changing third position is reached by rotating the shackle from its usual open position and then pushing the long leg portion of the shackle into the internal cavity.

10. A combination padlock as set forth in claim I, further comprising means for preventing the combination of the padlock from being changed when the shackle is in the combination-changing third position unless the tumblers are set to the opening combination.

H. A combination padlock as set forth in claim 4, wherein the locking means comprises a fence member having one end slidably connected to rail means provided by the body, having engagement means near its other end for releasably engaging the short leg portion of the shackle for releasably locking the shackle in the closed position, and having projecting means intermediate the one end and the engaging means, and a spring which acts against the fence member between the one end and the projecting means for biasing the one end of the fence member toward one end of the rail means and for biasing the projecting into contact with the peripheries of the tumblers, the engagement means en gaging the short leg portion of the shackle for locking the shackle when the shackle is in the closed position and the projecting means being receivable by notches in the peripheries of the tumblers for moving the engagement means out of engagement with the short leg portion of the shackle to unlock the shackle when the tumblers are set to the opening combination.

12. A combination padlock as set forth in claim 11, wherein the fence member is cooperable with means provided by the shifter plate for preventing the opening combination of the padlock from being changed when the shackle is in the combination-changing position unless the tumblers are set to the opening combination.

13. A combination padlock comprising:

a body having an internal cavity;

a shackle having a long leg portion and a short leg portion, the long leg portion being slidably supported by the body for enabling the shackle to be moved from an open first position to a closed second position;

a manually rotatable dial supported by the body;

a plurality of tumblers contained in the internal cavity, the tumblers being rotatable by the dial;

a fence member having one end slidably connected to rail means provided by the body, having engagement means near its other end for engaging the short leg portion of the shackle, and having projecting means, intermediate the one end and the engagement means; and

a spring which acts against the fence member between the one end and the projecting means for biasing the one end of the fence member toward one end of the rail means and for biasing the projecting means into contact with the peripheries of the tumblers,

whereby the engagement means engages the short leg portion of the shackle to releasably lock the shackle when the shackle is in the closed position, the projecting means being receivable by notches in the peripheries of the tumblers for moving the engagement means out of engagement with the short leg portion of the shackle to unlock the shackle when the tumblers are set to a predetermined opening combination.

14. A combination padlock as set forth in claim 13, wherein the engagement means comprises an opening in the fence member, the opening being cooperable with a projection on the short leg portion of the shackle for releasably locking the shackle in the closed position.

15. A combination padlock as set forth in claim 13, wherein the rail means comprises a wall and wherein the one end of the fence member has a notch in its side in sliding engagement with the wall.

16. A combination padlock as set forth in claim 13, wherein the part of the fence member between the engagement means and the other end is curved away from the short leg portion of the shackle when the shackle is in the closed position.

17. A combination padlock as set forth in claim 13, wherein the projecting means comprises a projecting rib formed in the fence member.

18. A combination padlock as set forth in claim 13, further comprising a ring disposed in the internal cavity and rotatable by a key, the ring having means for moving the engagement means of the fence member out of engagement with the short leg portion of the shackle for unlocking the shackle when the ring is rotated in a first direction by the key.

19. A combination padlock comprising a body having an internal cavity;

a shackle having a long leg portion and a short leg portion, the long leg portion being slidably supported by the body for enabling the shackle to be moved between an open first position and a closed second position;

a manually rotatable dial supported by the body;

a plurality of tumblers contained in the internal cavity, the tumblers being rotatable by the dial;

locking means in the internal cavity for releasably engaging the short leg portion of the shackle to releasably lock the shackle in the closed position; and

a ring disposed in the internal cavity and rotatable by a key, the periphery of the ring having gear teeth cooperable with teeth on the key, the ring having means for moving the locking means out of engagement with the short leg portion of the shackle for unlocking the shackle when the ring is rotated in a first direction by the key.

20. A combination padlock as set forth in claim 19, wherein the ring includes means cooperable with means provided by the body for limiting rotation of the ring in a second direction opposite the first direction,

21. A combination padlock as set forth in claim 19,

wherein the key comprises a spline shaft. 

1. A combination padlock comprising: a body having an internal cavity; a shackle having a long leg portion and a short leg portion, the long leg portion extending into the internal cavity and being slidably supported by the body for enabling the shackle to be moved from an open first position to a closed second position and to a combination-changing third position; a manually rotatable dial supported by the body; a plurality of tumblers contained in the internal cavity, the tumblers being rotatable by the dial; locking means cooperable with the tumblers for locking the shackle in the closed second position and for unlocking the shackle when the tumblers are set to the opening combination of the padlock; and combination-changing means actuated by the long leg portion of the shackle when the shackle is moved to the combinationchanging third position for enabling the opening combination of the padlock to be changed.
 2. A combination padlock as set forth in claim 1, wherein the tumblers releasably engage associated tumbler drivers, the drivers being rotatable by the dial, and wherein the combination-changing means comprises means for disengaging the tumblers from their associated drivers when the shackle is in the combination-changing third position, thereby enabling the drivers to be manually rotated relative to their associated tumblers by the dial for setting a new opening combination.
 3. A combination padlock as set forth in claim 2, wherein the means for disengaging the tumblers from their associated drivers comprises shifter means for shifting the tumblers relative to their associated drivers in a direction substantially along the axis of rotation of the tumblers.
 4. A combination padlock as set forth in claim 3, wherein the shifter means comprises a shifter plate having one end pivotally supported by the body and the other end biased into contact with means provided by the long leg portion of the shackle, the shifter plate carrying a pair of spaced side plates having slots receiving the peripheral edges of the tumblers, movement of the shackle from the open first position to the combination-changing third position causing the side plates to be moved in directions substantially parallel to said axis for moving the tumblers out of engagement with their associated drivers.
 5. A combination padlock as set forth in claim 4, wherein the means provided by the long leg portion of the shackle has means for scrambling the combination as the shackle is moved from the closed position to the open position.
 6. A combination padlock as set forth in claim 1, wherein the locking means comprises a fence member having one end slidably connected to rail means provided by the body, the fence member having engagement means near its other end for releasably engaging the short leg portion of the shackle to lock the shackle in the closed position, and having projecting means intermediate the one end and the engagement means, and a spring which acts against the fence member between the one end and the projecting means for biasing the one end of the fence member toward one end of the rail means for biasing the projecting means into contact with the peripheries of the tumblers, the engagement means engaging the short leg portion of the shackle for locking the shackle when the shackle is in the closed position and the projecting means being receivable by notches in the peripheries of the tumblers for moving the engagement means out of engagement with the short leg portion of the shackle to unlock the shackle when the tumblers are set to the opening combinations.
 7. A combination padlock as set forth in claim 1, further comprising a ring disposed in the internal cavity and rotatable by a key, the ring having means for moving the engagement means of the fence member out of engagement with the short leg portion of the shackle when the ring is rotated in a first direction by the key.
 8. A combination padlock as set forth in claim 6, further comprising a ring disposed in the internal cavity and rotatable by a key, the ring having means for moving the engagement means of the fence member out of engagement with the short leg portion of the shackle when the ring is rotated in a first direction by the key.
 9. A combination padlock as set forth in claim 1, wherein the combination-changing third position is reached by rotating the shackle from its usual open position and then pushing the long leg portion of the shackle into the internal cavity.
 10. A combination padlock as set forth in claim 1, further comprising means for preventing the combination of the padlock from being changed when the shackle is in the combination-changing third position unless the tumblers are set to the opening combination.
 11. A combination padlock as set forth in claim 4, wherein the locking means comprises a fence member having one end slidably connected to rail means provided by the body, having engagement means near its other end for releasably engaging the short leg portion of the shackle for releasably locking the shackle in the closed position, and having projecting means intermediate the one end and the engaging means, and a spring which acts against the fence member between the one end and the projecting means for biasing the one end of the fence member toward one end of the rail means and for biasing the projecting into contact with the peripheries of the tumblers, the engagement means engaging the short leg portion of the shackle for locking the shackle when the shackle is in the closed position and the projecting means being receivable by notches in the peripheries of the tumblers for moving the engagement means out of engagement with the short leg portion of the shackle to unlock the shackle when the tumblers are set to the opening combination.
 12. A combination padlock as set forth in claim 11, wherein the fence member is cooperable with means provided by the shifter plate for preventing the opening combination of the padlock from being changed when the shackle is in the combination-changing position unless the tumblers are set to the opening combination.
 13. A combination padlock comprising: a body having an internal cavity; a shackle having a long leg portion and a short leg portion, the long leg portion being slidably supported by the body for enabling the shackle to be moved from an open first position to a closed second position; a manually rotatable dial supported by the body; a plurality of tumblers contained in the internal cavity, the tumblers being rotatable by the dial; a fence member having one end slidably connected to rail means provided by the body, having engagement means near its other end for engaging the short leg portion of the shackle, and having projecting means, intermediate the one end and the engageMent means; and a spring which acts against the fence member between the one end and the projecting means for biasing the one end of the fence member toward one end of the rail means and for biasing the projecting means into contact with the peripheries of the tumblers, whereby the engagement means engages the short leg portion of the shackle to releasably lock the shackle when the shackle is in the closed position, the projecting means being receivable by notches in the peripheries of the tumblers for moving the engagement means out of engagement with the short leg portion of the shackle to unlock the shackle when the tumblers are set to a predetermined opening combination.
 14. A combination padlock as set forth in claim 13, wherein the engagement means comprises an opening in the fence member, the opening being cooperable with a projection on the short leg portion of the shackle for releasably locking the shackle in the closed position.
 15. A combination padlock as set forth in claim 13, wherein the rail means comprises a wall and wherein the one end of the fence member has a notch in its side in sliding engagement with the wall.
 16. A combination padlock as set forth in claim 13, wherein the part of the fence member between the engagement means and the other end is curved away from the short leg portion of the shackle when the shackle is in the closed position.
 17. A combination padlock as set forth in claim 13, wherein the projecting means comprises a projecting rib formed in the fence member.
 18. A combination padlock as set forth in claim 13, further comprising a ring disposed in the internal cavity and rotatable by a key, the ring having means for moving the engagement means of the fence member out of engagement with the short leg portion of the shackle for unlocking the shackle when the ring is rotated in a first direction by the key.
 19. A combination padlock comprising a body having an internal cavity; a shackle having a long leg portion and a short leg portion, the long leg portion being slidably supported by the body for enabling the shackle to be moved between an open first position and a closed second position; a manually rotatable dial supported by the body; a plurality of tumblers contained in the internal cavity, the tumblers being rotatable by the dial; locking means in the internal cavity for releasably engaging the short leg portion of the shackle to releasably lock the shackle in the closed position; and a ring disposed in the internal cavity and rotatable by a key, the periphery of the ring having gear teeth cooperable with teeth on the key, the ring having means for moving the locking means out of engagement with the short leg portion of the shackle for unlocking the shackle when the ring is rotated in a first direction by the key.
 20. A combination padlock as set forth in claim 19, wherein the ring includes means cooperable with means provided by the body for limiting rotation of the ring in a second direction opposite the first direction.
 21. A combination padlock as set forth in claim 19, wherein the key comprises a spline shaft. 